Showing papers by "Marche Polytechnic University published in 1991"

A controlled study of inhaled pentamidine for primary prevention of Pneumocystis carinii pneumonia.

Abstract: BACKGROUND: Current recommendations for prophylaxis of Pneumocystis carinii pneumonia (PCP) are based on data from patients who have had at least one episode of PCP (secondary prevention). We designed a study to determine the efficacy and side effects of inhaled pentamidine in the primary prevention of PCP. METHODS: Two hundred twenty-three patients sero-positive for human immunodeficiency virus (HIV) who had the acquired immunodeficiency syndrome (AIDS) but not PCP, who had advanced AIDS-related complex, or who had less than 0.2 x 10(9) CD4-positive lymphocytes per liter received either 300 mg of pentamidine isethionate or 300 mg of sodium isethionate every 28 days by inhaler. The proportion of patients surviving without PCP was analyzed with the log-rank test as a function of time spent in the trial, according to the intention to treat with either placebo or pentamidine. RESULTS: The third of five planned interim analyses showed a significant difference in the occurrence of PCP, with 8 cases in pentamidine group and 23 in the placebo group (nominal P value = 0.0021). There were no deaths within 60 days of the diagnosis of PCP and no significant differences in survival between groups. Approximately 53 inhalations were needed to prevent one episode of pneumonia. Thirty-eight of 114 patients given pentamidine (33 percent) and 7 of 109 given placebo (6 percent) had moderate-to-severe coughing during inhalations (two-tailed P less than 0.00001), which caused 4 patients given pentamidine (3.5 percent) to discontinue taking it. CONCLUSIONS: A dose of 300 mg of aerosolized pentamidine given every four weeks was well tolerated and 60 to 70 percent effective in preventing a first episode of PCP in patients with HIV infection.

Psychologic reactions of patients undergoing magnetic resonance imaging. Preliminary study

Abstract: MR imaging, like other imaging techniques, can cause emotional and psychological reactions in the patients Although reversible, these reactions sometimes lead the patient to absolutely refuse the examination or to make it impossible to carry it through To investigate the patients' emotional distress, a study group of 28 subjects was examined They were heterogeneous in sex, age, and pathologic condition The main psychological reactions were analyzed, and anxiety--both of state and of trait The anxiety parameter was evaluated as a specific index in the psycho-behavioral modifications induced by MR examination The influence was also considered of the "fantasies" related to examination results on the patients' psyche Talks and STAI X1 and STAI X2 were employed to this purpose, to identify possible disturbing elements related to both patients' character and examination situations Our results point to anxiety as the major reaction observed in the subjects undergoing MR examination; it seems to be related to different parameters, which are difficult to identify Claustrophobia, pathofobia, and the fear of an unknown examination play a major role Talking to the patients and informing them of the characteristics of the examination proved useful to significantly reduce their emotional distress

The effects of antihypertensive therapy on renal function.

Abstract: Renal vascular resistance is increased in essential hypertension, with a consequent reduction in renal plasma flow together with a normal or slightly reduced glomerular filtration rate. Non-specific vasodilators may exacerbate this effect while loop diuretics, beta-blockers, angiotensin converting enzyme inhibitors and calcium antagonists may increase these renal hemodynamic parameters. We studied the effect of lacidipine, a new long-lasting calcium antagonist, on renal hemodynamics in 11 essential hypertensives. Lacidipine (4 mg once a day) acutely increased renal plasma flow without affecting the glomerular filtration rate. A transient, but non-significant, diuresis and natriuresis occurred. After 4 weeks of lacidipine treatment, all the parameters of renal function returned to basal levels. These results suggest that the well known renal effects of calcium antagonists are, at least in part, related to the onset of the antihypertensive effect being more pronounced with compounds such as nifedipine which have a rapid-onset, blood pressure-lowering effect.

Identification of human postural control

Abstract: Black box modelling and identification was applied to the motor-sensory feedback of a posture control system without external disturbances, The standing upright subject was modelled using an inverted-pendulum model. Analysis was extended to 28 healthy subjects engaged in cognitive verbal and visuo-spatial tasks, Further, 3 pathological subjects were examined, who were suffering from multiple sclerosis. The transfer function of the whole closed loop system was then considered, and the relative poles were computed, The distribution of the above poles on the z-plane showed an overall stabilizing effect of the cognitive tasks, both for healthy and pathological subjects, if compared to stance with open and closed eyes. Between the two tasks, the visuo-spatial one was found to be more stabilizing than the verbal one. On the other hand, differences on the model order of the controller were found among the tested pathological and healthy people. In fact the order remained unchanged both interindividually for healthy subjects performing the same task, both among different tasks performed by the same subject. Instead, pathological subjects were found to be characterized by a different model order, with respect to the healthy population, for the controller block of the posture control system.

[Effect of HMG-CoA reductase inhibitors on the erythrocyte membrane].

Abstract: We studied 10 patients affected by primary hypercholesterolemia treated with placebo for 1 month and with simvastatin (20 mg die) for 6 months during a double-blind clinical trial. At 1-month intervals we determined the following parameters in the serum: total and HDL-cholesterol, triglycerides, apolipoprotein A1 and B. At the same time intervals, we also determined the cholesterol and phospholipid concentration, the Na+/K+ ATPase activity and the fluidity of the erythrocyte membranes. Our results demonstrated the following modifications in the erythrocyte membranes during simvastatin treatment: 1) an initial increase in the cholesterol concentration and in the cholesterol/phospholipid ratio, with a significant decrease only after 4 months; 2) a similar behaviour of membrane fluidity, with an initial decrease and an elevation after 4 months; 3) an increase in the Na+/K+ ATPase activity only after 4 months. We hypothesize that simvastatin not only inhibits the hepatic synthesis of cholesterol, but also modifies the cholesterol exchange between plasma and the erythrocyte membrane.